The present invention relates to a method for optimizing the rank of channel matrix, a wireless base and a mobile station. More particularly, the present invention relates to a method for optimizing the rank of channel matrix using the state data of a mobile station as well as a wireless base and a mobile station.
In a Multiple-Input Multiple-Output (MIMO) communication system, the communication state of a mobile station itself is detected to determine the rank of channel matrix applicable to the mobile station. The mobile station performs the Channel State Information (CSI) detection according to the determined rank of channel matrix, and notifies the result of the detection to a wireless base, so that the wireless base is able to determine the data flow to be transmitted to the mobile station according to the rank of channel matrix determined by the mobile station and the corresponding result of the channel detection. However, in a conventional method for determining the rank of channel matrix, the rank of channel matrix applicable to a mobile station are determined according to only the result of the detection of the communication state of the mobile station itself without considering the interference between mobile stations.
On the other hand, in order to improve the capacity of a communication system, a communication system in which multiple mobile stations may share a same time and/or frequency resource has been proposed. For example, in a Non-Orthogonal Multiple Access (NOMA) system, multiple mobile stations connected to a same wireless base may form a mobile station pair, mobile stations in each mobile station pair share same time and frequency resources, and mobile stations in the mobile station pair are distinguished from each other by the transmission power. However, in such a communication system, the problem that there is the interference between multiple mobile stations sharing same time and/or frequency resources is more prominent. This leads to that the rank of channel matrix of the mobile station determined according to only the result of the detection of the communication state of the mobile station itself may not be optimal, thus influencing the communication state of the mobile station, for example, throughput and the like.